1. Field of the Invention
This invention relates generally to tracking images and identifying sensor of origin. More particularly, the present invention relates to a method and apparatus for camera sensor identification via an etched flaw.
2. History of the Prior Art
There has be an explosion in the number of digital imaging systems available to consumers as higher performance products are being offered at lower prices. Some of the more popular consumer applications include digital video, scanners, copiers, facsimile, and digital cameras. Efforts to develop more advanced digital cameras are fueled by the continued expansion of high performance personal computers in both homes and businesses. Today""s computers have the data processing capabilities to manipulate and display the data of digital images.
Digital camera manufacturers have been striving to improve the digital imaging system in a number of ways. Systems are being designed to yield improved digital image quality in an effort to match that of the conventional chemical film cameras. There are also efforts to reduce the power consumption required for battery-operated systems such as digital cameras. However, one area that is of interest for improvements is security and image tracking.
Existing digital cameras provide for the attachment of data such as messages, captions, or dates to images. However, the data is generally user controlled and may be fraudulently modified. Similarly, other art such as the Advanced Photo System(trademark) (APS) stores data related to film format or cassette information in a special recording layer in the film. For instance, some APS cameras record reprint information invisibly on the film""s magnetic layer. But these methods do not provide for storing an identifier that could be used in identifying the sensor from which the image came from. Users may be interested in the tracking of images taken with a particular sensor, especially in security applications or manufacturing. Currently, no such identifier is currently available.
Hence it would therefore be desirable to have a method and apparatus for tracking images and identifying its sensor of origin.
The present invention introduces a method and apparatus for camera sensor identifier via an etched flaw. The method of the present invention first fabricates a solid-state image sensor. The image sensor comprises of a plurality of transistors. Then a subset of said transistors are modified to create an identifier. Modification may entail the use of a laser or electron beam to alter a subset of said transistors.
Other objects, features, and advantages of the present invention will be apparent from the accompanying drawings and from the detailed description that follows.